非晶态Fe_(90-x)V_xZr_(10)合金吸氢现象及磁性变化的研究

利用Mossbauer谱、磁测量技术,X射线衍射以及二次离子质谱分析(SIMS)技术,对三元非晶合金Fe_(90-x)V_xZr_(10)吸氢现象及磁性变化进行了研究.实验结果表明:随充氢时间(相同的充氢电流密度)的增加,非晶态合金同质异能移位增加,表明充氢后Fe核处电子密度发生变化.随充氢量增加,室温下合金由顺磁状态转变为铁磁状态,超精细分布逐渐展宽,其最大值也向高场方向移动.吸氢后合金原子磁矩及Curie温度T_C有大幅度增加.0K时饱和磁化强度从未充氢合金的120emu/g增加到174emu/g.Curie温度T_C从257K增加到384K.吸氢导致磁性变化的机理,利用杂化理论模型能够给出很好的解释.     

非晶态Fe_(90-x)Si_xZr_(10)合金的磁矩,Curie温度和自旋波激发

非晶态Fe_(90-x)Si_xZr_(10)(x=0,4,7,10)合金是用单辊急冷方法制备的,用提拉样品磁强计测量了样品的磁化曲线和热磁曲线。发现每个磁性原子的平均磁矩μ和Curie温度T_c随Si含量的增加而增加,与相应的非晶态FeSiB合金相比,非晶态FeSiZr合金的μ和T_c明显偏低,认为这一反常现象是Fe-Fe原子间的反铁磁耦合的存在所致。低温下样品的磁化强度与温度的关系较好地符合Bloch T~(3/2)定律,得到自旋波劲度系数D从x=0时的0.37meV·um~2增加到x=10时的0.538meV·um~2,计算出交换相互作用范围都是在最近邻原子间的距离。     

非晶态Co90—xCrxZr10合金的磁性和晶化

本文研究了非晶态Co_(90-x)Cr_xZr_(10)(0≤x≤25)合金的磁性,得到样品的Curie温度T_C和每个磁性原子的有效磁矩μ均随Cr含量x的增加近似线性下降,计算出每个Co和Cr原子的平均磁矩分别为μ_(Co)=1.51μ_B和μ_(Cr)=-3.62μ_B低温下的磁化强度与温度的关系符合Bloch的T~(3/2)定律,由此算出的自旋波劲度系数D从x=4时的D=2.788meVnm~2下降到x=20时的D=0.727meVnm~2,相互作用范围从x=4时的2—3个原子减小到x=20时的最近邻原子之间,样品的晶化温度随Cr含量x的增加单调上升,认为与合金的平均外层电子浓度有关,用X射线衍射和热磁测量分析了热处理样品的结晶相。     

非晶态Fe_（90－x）Co_xZr_（10）合金的Invar效应研究

研究了作晶态Ｆｅ_（９０－ｘ）Ｃｏ_ｘＺｒ_（１０）合金的磁体积效应和广义声子谱．通过热膨胀测量和磁测量给出了自发体积磁致伸缩ωｓ和平均磁矩μ_（ＦｅＣｏ）与平均价电子数Ｎ_（ｅｆｆ）的关系，发现ωｓ的峰值位置与μ_（ＦｅＣｏ）开始急剧下降的位置（Ｎ_（ｅｆｆ）＝８．１－８．２）相对应，从而证实了金属－金属型非晶态因瓦合金中的Ｉｎｖａｒ效应与铁磁态的不稳性有关．用非弹性中子散射方法测量了广义声子谱，从中观察到了与Ｉｎｖａｒ效应相关的声子谱软化现象．     

MAGNETIC PROPERTIES AND CRYSTALLIZATION OF AMORPHOUS ALLOYS Co_(90-x)Cr_xZr_(10)

Curie temperature of amorphous alloys Co_(90-x)Cr_x Zr_(10) decreases linearly with increas-ing x.Average magnetic moment per magnetic atom Co or Cr is 1.51 μB or -3.62 μBrespectively.The temperature dependence of spontaneous magnetization at low temper-atures is in agreement with Bloch's T~(3/2) law.The spin wave stiffness constant decreaseswith increasing x from 4 to 20.The range of interaction is 2—3 atoms for x=4 andnearest neighbour atom for x=20.The crystallization temperature increases mono-tonically with increasing x.It may relate to the average number of outer electrons peratom.The crystalline phase components of heat-treated alloys were analyzed by X-raydiffration and thermomagnetic measurement.     

非晶态Fe90—xNixZr10合金的起始磁化率减落

测量了非晶态Fe_(90-x)Ni_xZr_(10)(x=10,20,30)合金淬态和预处理态(573K,45min)样品的起始磁化率等时减落谱和等温减落谱,在等时减落谱的低温区(T<300K)观察到一伴随小峰,本文用二能级模型分析了弛豫过程的可逆性和热处理效应,对可逆减落谱的理论拟合给出可逆弛豫过程的激活能谱P(Q)和特征弛豫时间τ_(OR)。     

Nd_xB_（20－x）Fe_（78）Cu_（0．3）Co_（1．7）系非晶合金

本文测量了经不同温度和时间真空退火的非晶合金带Ｎｄ_ｘＢ_（２０－ｘ）Ｆｅ_（７８）Ｃｕ_（０．３）Ｃｏ_（１．７）（ｘ＝０．１，２，３，４，５），在１ｋＨｚ交流电下的磁化曲线，发现含少量Ｎｄ的非晶合金带在晶化温度附近真空退火后、起始导磁率减小，饱和场增大，使材料从软磁性向硬磁性转化；随着Ｎｄ含量的增加，这种转化重明显．Ｘ射线衍射透射电镜观察及电子衍射分析表明，材料在初期晶化时能析出颗粒大小为５－１００ｎｍ的针状纳米晶，且随着Ｎｄ含量增加，针状纳米晶的数量增多，这一现象与材料磁性测量的结果吻合．     

DISACCOMMODATION OF INITIAL SUSCEPTIBILITY IN AMORPHOUS Fe_(90-x)Ni_xZr_(10) ALLOYS

The disaccommodation(DA)measurements of initial susceptibility were performed inamorphous Fe_(90-x)Ni_xZr_(10)(x=10,20,30)alloys.The DA was measured for two differentamorphous states:as-quenched and pretreated at 537 K for 45 min.For all the as-quenched samples,in the isochronal spectra of DA a well defined relaxation peak around350 K is accompanied by a samll but distinct peak near the Curie temperature ofFe_(90)Zr_(10) phase(T_c=230 K).The reversibility and annealing effect on DA are analyzedwithin the framework of two-level model.The fits of the theory to the experimentaldata of reversible relaxation processes gave a spectrum,of activation energies and pre-exponential factor.     

Fe-Ni-Mo-(Si)-B非晶的晶化及纳米晶合金磁性的研究

对Ｆｅ４０Ｎｉ３８Ｍｏ４Ｂ１８,Ｆｅ３８Ｎｉ３５Ｍｏ４Ｓｉ５Ｂ１８、Ｆｅ３９Ｎｉ３６Ｍｏ２Ｓｉ５Ｂ１８（均为原子分数,％）三种非晶合金在４００－５２０℃等温退火１小时后的晶化行为进行了研究。并研究了Ｆｅ４０ｉ３８Ｍｏ４Ｂ１８合金的磁性。结果表明：Ｆｅ４０Ｎｉ３８Ｍｏ４Ｂ１８,合金经４３０－４５０℃温度退火后,在非晶基体上析出了ｆｃｃγ－（Ｆｅ,Ｎｉ）固溶体,平均晶粒尺寸Ｄ接近１０ｎｍ,具有很好的软     

非晶态Fe_(1-x)(Si,B)_x合金的内禀磁性和磁各向异性

非晶态Fe_(1-x)(Si,B)_x合金的磁矩和磁致伸缩随着Si和B含量的增多而缓慢降低,而Curie温度约在25%(Si+B)含量时呈现出最大值;Si与B的含量对磁各向异性并无明显影响,但表面条纹退磁效应对磁各向异性却有较大的影响。这些实验现象可以借助电子转移和非晶态合金的结构模型得到定性的解释。     

INTRINSIC MAGNETISM AND MAGNETIC ANISOTROPY OF AMORPHOUS Fe_(1-x)(Si,B)_x ALLOYS

The magnetic moment and the magnetostriction decrease slightly with the increase of totalSi+B content.A maximum of the Curie temperature appears at about 25 at.-% of Si+B.Themagnetic anisotropy is uninfluential by the content of Si+B,but much influnce by thedemagnetization effect of streak.A qualitative explanation of the experimental phenomenonseems to be noted by the aid of the electron transition and structure model of amorphous al-loys.     

MAGNETIC MOMENT,CURIE TEMPERATURE AND SPIN WAVE EXCITATION FOR AMORPHOUS Fe_(90-x)Si_xZr_(10) ALLOYS

The magnetization curves at 1.5 K and thermomagnetic curves for amorphous Fe_(90-x)Si_xZr_(10)(x=0,4,7 and 10)alloys prepared by the drum spinning technique have been measured with an extracting sample magnetometer.It is obtained that the average magnetic moment,,per magnetic atom and Curie temperature,T_c,in the amorphous FeSiZr alloys increase with increasing Si content.The and T_c are found to be quite small,compared with amorphous FeSiB alloys.This unusual behavior is suggested to be due to the presence of the Fe—Fe antiferromagnetic interactions.The temperature dependence of magnetization at lower temperature is in accordance with Bloch's T~(3/2) law.Calculation shows that the spin wave stiffness constant,D,increases with increasing Si content from 0.37 meV·nm~2 for x=0 to 0.538 meV·nm~2 for x=10.The values ofindicate that the range of the exchange interaction is roughly the mean atomic distance of nearest neighbours.     

CRYSTALLIZATION AND MAGNETIC PROPERTIES OF AMORPHOUS Nd_6Fe_(81)B_(13)ALLOY

The magnetic properties and the crystallization and its influence on the magnetic and struc-tural properties for rapidly quenched amorphous Nd_6Fe_(81)B-(13) alloy have been studied.The lowtemperature magnetic properties,the Curie temperature and the crystallization behavior arediscussed.A small addition(6at.-%)of Nd in amorphous Fe-B alloys increases largely thecrystallization temperature T_x but causes a decrease of the Curie temperature Tc·A newphase was observed in the sample annealed at 873 K.     

快淬（Fe1—xGax）77.5Nd4B18.5合金的磁性及其晶化行为

研究了快淬(Fe_(1-x)Ga_x)_(77.5)Nd_4 B_(18.5)合金的磁性,晶化行为,以及Ga含量和热处理对其硬磁性和相组成的影响,结果表明随着Ga含量x的增加,非晶态样品的Curie温度提高,而晶化温度降低,Fe原子的平均磁矩近似为一个常数,用X射线衍射和热磁测量分析了热处理后样品的结晶相,还研究了室温矫顽力与Ga含量的关系。     

MAGNETIC PROPERTIES AND CRYSTALLIZATION BEHAVIOR OF AN AMORPHOUS（Fe＿（1－x）Mo＿x）＿（79）Si＿9B＿（13）ALLOY

ＭＡＧＮＥＴＩＣＰＲＯＰＥＲＴＩＥＳＡＮＤＣＲＹＳＴＡＬＬＩＺＡＴＩＯＮＢＥＨＡＶＩＯＲＯＦＡＮＡＭＯＲＰＨＯＵＳ（Ｆｅ＿（１－ｘ）Ｍｏ＿ｘ）＿（７９）Ｓｉ＿９Ｂ＿（１３）ＡＬＬＯＹＭＡＧＮＥＴＩＣＰＲＯＰＥＲＴＩＥＳＡＮＤＣＲＹＳＴＡＬＬＩＺＡＴＩ...     

硼含量对Fe-Zr-B-Nb非晶合金的晶化、形成能力和磁性能的影响

用快冷法制备了Fe91-xZr5BxNb4(FZBN)合金,当x=5-30时,样品为非晶态.研究了B含量对非晶合金的晶化、玻璃形成能力(GFA)和磁性能的影响. FZBN的GFA在其共晶成分x=27.5附近达到极大值.当x≤20时, FZBN非晶合金以一次晶化的模式晶化;当2020时,由于晶化模式的改变,不仅Tg,Tx和GFA突然迅速增加,而且TC,Ms以和Hc及其随x变化的规律也发生变化.FZBN非晶合金在高B含量区(25≤x≤30)具有很好的GFA、热稳定性和软磁性能.     

MOSSBAUER STUDY ON MAGNETIC ANISOTROPY OF AMORPHOUS ALLOY Fe_(71)Ni_(10)B_(13)Si_4C_2

Magnetic anisotropies of the amorphous alloy Fe_(71)Ni_(10)B_(13)Si_(14)C_2 annealed in magnetic fieldhave been studied using Mossbauer spectroscopy and X-ray diffraction.It is shown that thedistribution of moments in the annealed sample are determined by both stress-produced andthermomagnetic treatment-induced magnetic anisotropies.     

氢对Zr41.2Ti13.8Cu12.5Ni10Be22.5块状非晶光谱特性的影响

利用电弧熔炼及铜模快速铸造的方法制备zr41.2Ti13.8cu12．5Ni10Be22.5块状非晶合金，通过电化学方法向块状非晶中充入氢．研究了充氢对该非晶态材料反射光谱、吸收光谱、透射光谱特性的影响．结果表明，充氢掺杂后，提高反射率，降低吸收率，降低红外光的透射率，并使反射峰向短波边移动．     

部分非晶态Fe_(33)Zr_(67)合金条带的表观晶化动力学

利用示差扫描量热卡计（ＤＳＣ），结合Ｘ射线衍射分析（ＸＲＤ）及透射电子显微镜分析（ＴＥＭ）等实验，研究了部分非晶态Ｆｅ３３Ｚｒ６７合金条带的晶化动力学结果表明：晶化过程为晶粒长大过程所控制，尽管在条带中淬态核分布明显不均匀，与经典Ａｖｒａｍｉ分析的基本假设相矛盾，但该晶化过程仍然与ＪＭＡ反应动力学结论一致．     

非晶态合金磁性能与结构参数的定量关系

用结构参数－模式识别／人工神经网络（ＡＮＮ）方法对非晶态合金的磁性（包括饱和磁致伸缩系数，饱和磁感应强度，矫顽力）与组成，结构之间的关系进行了定性分析和定量计算，采用的结构参数有平均价电子数，混合熵，原子半径经，电负性差，功函数差和电子密度差等。结果表明，定性分析结果与实验结论一致，定量计算结果与实验测定值符合较好。